Preparation of highly pure copper oxide from waste etchant

Abstract

A method for recycling copper oxide includes: a first step in which a sodium hydroxide aqueous solution is added to acidic copper chloride waste etchant produced in the PCB industry, to obtain copper hydroxide slurry; and a second step in which the slurry obtained in the first step is heated and sintered to thereby prepare a needle-form copper oxide. Since copper oxide has a purity of more than 99.0 wt % and the needle-form crystal morphology, so that it has an excellent filtering ability and homogeneous particle size distribution.

What is claimed is:  
     
       1. A method for preparing copper oxide, comprising the following steps of: 
       a) adding an aqueous sodium hydroxide solution to an acidic copper chloride waste etchant at a temperature of 10-30° C., to obtain copper hydroxide slurry;  
       b) aging the obtained copper hydroxide slurry at a temperature of 50-100° C., to obtain copper oxide in needle form having a purity of more than 99.0 wt %; and  
       c) sintering the obtained copper oxide at a temperature of 100-400° C.  
     
     
       2. The method according to  claim 1 , wherein 820 g to 1,100 g of 33 wt % aqueous sodium hydroxide solution is added per 1 liter of acidic copper chloride waste etchant, having a composition of 19-25.5 wt % CuCl 2 , 7-10 wt % of HCl and 64.5-74 wt % of H 2 O. 
     
     
       3. The method according to  claim 1 , wherein the aging in step b) is carried out for one to three hours.